锰对ZA27合金压缩蠕变的影响

Effect of Mn on creep kinetics in compression of ZA27 alloy

为了解质量分数为0 5%Mn对铸态ZA27合金压缩蠕变行为的影响,采用自制的试验装置研究了ZA27-Mn合金和ZA27合金第一阶段的压蠕变量和稳态蠕变速率.结果表明:ZA27-Mn合金第一阶段的压蠕变量和稳态蠕变速率低于ZA27合金,而两种合金的压蠕变均符合于lnt=C-nlnσ+Q/RT,ZA27-Mn合金的应力指数(n)和蠕变激活能(Q)分别为3 83和82 76kJ·mol-1,而ZA27合金的应力指数和蠕变激活能分别为3 46和81 09kJ·mol-1,材料结构常数C不同,合金压蠕变不同,ZA27-Mn合金的压蠕变抗力高于ZA27合金;加入0 5%Mn对ZA27合金蠕变机制并无影响,均是锌的点阵自扩散和位错的攀移机制.

In order to understand the effect of 0.5%Mn on the compressive creep behavior of as cast ZA27 alloy, the primary compressive creep strain and steady creep rate of the ZA27-Mn alloy and the ZA27 alloy were investigated with special apparatus. The results showed that the primary compressive creep strain and steady creep rate of the ZA27-Mn alloy was lower than that of the ZA27 alloy. The compressive creep in both ZA27-Mn alloy and ZA27 alloy obeyed an empirical equation ln t=C-nln σ+Q/RT, and the exponent stress(n)3.83 for ZA27-Mn alloy and 3.46 for ZA27 alloy respectively, the activation energy(Q)82.76 kJ·mol^(-1) for ZA27-Mn alloy and 81.09 kJ·mol^(-1) for ZA27 alloy respectively.When different material structural constant(C)was associated with different compressive creep in this alloy, the compressive creep resistance of ZA27-Mn alloy was higher than that of ZA27 alloy in all range of temperature and stress used. But the addition of 0.5%Mn did not influence the compressive creep mechanism of ZA27 alloy, which was controlled by the lattice diffusion of zinc and dislocation limb.